Set the Integer pref browser.sessionstore.max_resumed_crashes to 0 on the about:config page to get the about:sessionrestore page immediately with the first restart after a crash has occurred or the Task Manager was used to close Firefox. * http://kb.mozillazine.org/browser.sessionstore.max_resumed_crashes *http://kb.mozillazine.org/about:config That way you see if the previous session didn't close properly or crashed and will allow you to deselect the tab(s) that you do not want to reopen, but will allow to reopen other tabs. ---- Clear the cache and the cookies from sites that cause problems. "Clear the Cache": *Tools > Options > Advanced > Network > Cached Web Content: "Clear Now" "Remove Cookies" from sites causing problems: *Firefox/Tools > Options > Privacy > Cookies: "Show Cookies"